Centerless grinding machine



June 25, 1940.

R. H. CRAMER CENTERLESS. GRINDING MACHINE Filed Oct. 2, 1939 INVENTOR;

12/4 YMOND H, 0 A Mill HIS ATTO RNVE Y. I

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Patented June 25, 1940 UNl'lED STATES 2,205,468 7 CENTERLESS GRINDINGMACHINE Raymond Ill. Cramer, Newark, N. 3., assignor to General MotorsCorporation, Detroit, Mich, a

- corporation of Delaware Application October- 2, 1939, Serial No.297,510

16 Claims.

This invention relates to centerless grinding machines and comprises allof the features and aspects of novelty herein disclosed. An object ofthe invention is to provide improved mechanism for grinding taperedarticles, especially bearing rollers which are conical or have theirperipheral surfaces generated by a curved surface of revolution, one endof the roller being larger than the other. Another object is to provideimproved mechanism for presenting tapered work to a centerless grindingmachine and giving the work a lateral cross feed movement against thegrinding wheel without raising or lowering the work with respect to theline of wheel centers. Another object is to provide improved mechanismfor feedingtapered work to and ejecting it from a centerless grindingmachine.

To these ends and also to improve generally upon machines of thischaracter, the invention consists in the various matters hereinafterdescribed and claimed. In its broader aspects, the invention isnotnecessarily limited to the specific constructions selected forillustrative purposes in the accompanying drawing in which I Fig. 1 is afront view, the grinding wheel being removed and the work supply chutesbeing in 7 section.

Fig. 2 is a right hand side view of Fig. 1.

Fig. 3 is a plan view, the chutes being omitted. Fig. 4 is a plan viewof a modification.

Fig. 5 is a front view of parts appearing in Fig. 4.

Fig. 6 is a right hand side view of Fig. 5.

Fig. 7 is a plan view of another modification.

The numeral id indicates a support having a dovetail slideway ii for aslide It which is reciprocated by any suitable mechanism between stopsitand I8 which are preferably thumb screws adjustably mounted in lugs onthe support ill. The slide it has an upright portion provided with apair of work receiving notches or pockets 2t and 2'2, each pocket havingbevelled entrance portions 2%, a substantially vertical pushing surface,and a work supporting rest'or blade 26 which is inclined downwardly awayfrom a grinding wheel 28 and towards aregulating wheel 30. Each blade 26also has a small longitudinal inclination such that a tapered roller Ror similar non-cylindrical work-piece will be supported with its axishorizontal or in a plane parallel to the slideway it. Such axisfas willlater appear, is not quite parallel to the direction of movement of theslide.

,-surfaces 32 and 34 which are inclined in opposite directions withrespect to the active surface of the grinding wheel so that thepermanently adjacent surfaces of the wheels form a pair of taperingthroats open in opposite directions, the degree of taper depending onthe work and being equal to the included angle of the tapered roller Rso that the roller will always have that element which is nearest tothegrinding wheel parallel to the active element of the l grindingwheel. Accordingly, when the bottom roller from a supply chute 36 dropsinto the pocket 20 and is subsequently'carried to the right by the slideM, the roller will also be given a lateral, cross feed movement towardsthe. grinding surface as such roller rides endwlse along the inclinedsurface 32. All portions in the length of the roller thus meet thegrinding wheel with equal cross feed movement. The crosswise inclinationof the blade 25 urges the roller against 33 the regulating wheel surface32 which controls rotation of the work before and after it meets thegrinding wheel.

When the roller R in the pocket 28 has been ground to size, which may becontrolled by the adjustable stop It, a left hand stroke of the slidewill carry the ground roller past the rollers in the supply chute 36 andinto line with an ejector or discharging member 38 which is preferablyslidable crosswise of the slide it. The ejector pushes the finishedroller out of the pocket 20 into an exit chute till. It will beunderstood that rollers stacked in a second chute d2 will feed into thesecond pocket 22 and be ground when the slide moves to the left and thateach such finished roller R2 will be pushed by a second ejector ordischarge member it into a second exit chute it when the slide completesthe next stroke to the right. The upper surface of the slide it acts asa barrier to hold the work in the supply chutes except when an emptypocket arrives under a chute.

It will be noted from Fig. 1 that the tapered rollers in the chute 3%have their larger ends at the left while the rollers in the chutedZ havetheir larger ends at the right. The work pushing surfaces at the ends ofthe pockets 20 and 22 are flat and in vertical planes slightly inclinedcrosswise of the slide to engage the large ends of the respectiverollers. Hence these surfaces aid the surfaces 32 and 34 and the blades26 in locating the rollers as the rollers are shifted towards grindingposition. Both blades incline crosswise in the same direction but theirlon tudinal inclinations are opposite. One chute, 55

one ejector, one work pocket and one of the surfaces 32 and 34 may ofcourse be omitted.

The grinding wheel is preferably cylindrical and the regulating wheelpreferably has its surfaces 32 and 34 conical but these shapes are notessential. The co-operating and permanently adjacent wheel surfacesdefine a grinding throat which is divergent; or tapering, the relativeinclination of the two surfaces being equal to the included angle of thetaper roller. The longitudinal inclination of the blade is half of theincluded angle to support the axis of the piecein a horizontal plane andis equal to the crosswise inclination of the vertical pushing surface ofthe pocket with respect to the wheel surfaces, the end faces of theroller being normal to the roller axis. The terms horizontal, vertical"and inclined are relative and are used for convenience in definition, itbeing obvious, for instance, that the slideway 12 need not be horizontaland that the entire apparatus could be tipped in a selected direction.

Figs. 4, 5 and 6 indicate a mechanism for grinding another kind oftapered roller C which is convex or rounded lengthwise. The grindingwheel comprises a concave surface 50 to'conform to the surface of theroller, the wheel also preferably having a tapered surface 32 leading tothe surface 50 and an extended portion 54. The regulating wheel has aconcave surface 56 conforming to the work surface and an extendedportion 51. A slide 58 is provided with a. pocket 60 for the rollers,the bottom of the pocket forming a work rest on blade conforming to thework surface and having a crosswise inclination downwardly towards theregulating wheel. The blade curvative and longitudinal inclination aresuch as to support the roller with its axis in a horizontal plane. Therollers are supplied to the pocket from a supply chute 62 in which thestacked rollers are normally held back by the angled top surface of theslide. The vertical end of the pocket pushes the roller into thedivergent throat formed by the adjacent wheel surfaces 50 and 55.

To prevent the rollers from dropping down beyond the end of theregulating wheel, a guide bar 84 is arranged along the upper edge of theslide and extends close to the wheel surface 56. The roller tends toroll towards the guide bar 64 and the regulating wheel as the slideadvances the roller between the wheels. Thus, rotation is imparted tothe roller before the grinding wheel begins to grind. The finishedroller is ejected when it is retracted to the left of the chute by theslide. If desired, the axis of the regulating wheel 58 may be slightlyinclined in a vertical plane and in a direction to urge the rollerbackwardly against the locating face provided by the vertical wall ofthe pocket 60.

In ,Fig. 7, apparatus for grinding concavely rounded rollers 68 isindicated. The apparatus is similar to that of Fig. 4' but the grindingwheel tom. or blade are convex to conform to the rollers. Two-waygrinding of the rounded rollers of Fig. 4 or Fig. '7 may be obtained byduplicating the curved surfaces of they wheels to provide a pair ofoppositely diverging grinding throats, and suplying a second pocket anda second chute as suggested by Fig. 1.

I claim:

1. In a centerless grinding machine, a grinding wheel,. a regulatingwheel, the adjacent surfaces of the wheels being relatively inclinedmouse to form a tapering throat, a shiftable work blade adapted to enterbetween the wheels and having its work engaging surface inclined bothlengthwise and crosswise to cause a conical work-piece to be locatedgravitationally bythe blade and the regulating wheel with an element ofthe conical work surface parallel to the active surface of the grindingwheel, and a slide for shifting the blade into the throat to carry theworkpiece endwise along the regulating wheel and thereby feed the piecelaterally against the grinding wheel; substantially as described.

2. In a centerless grinding machine, a grinding wheel, a regulatingwheel, the wheels having permanently adjacent surfaces relativelyinclined to define a tapering throat, a work carrying slide mounted toreciprocate with respect to the wheels substantially parallel to theactive portion of the grinding surface, the slide having a work bladeinclined lengthwise and peripherally supporting a tapered work-piece,and the slide also having a pushing surface fitting against one end ofthe work-piece and inclined crosswise with respect to the active surfaceof the grinding wheel; substantially as described.

3. In a centerless grinding machine, a grinding wheel,a regulatingwheel, thewheels having permanently adjacent surfaces relativelyinclined to define a tapering throat, a work carrying slide mounted toreciprocate with respect to the wheels substantially parallel to theactive portion of the grinding surface, a work blade carried by andshiftable with the slide, the blade having a lengthwise inclinationcorresponding to the taper of a work-piece, and such inclination beinghalf the relative inclination of the wheel surfaces; substantially asdescribed.

4. In a centerless grinding machine, a grinding wheel, a regulatingwheel, the wheels having permanently adjacent surfaces relativelyinclined to define a tapering throat, a work carrying slide mounted toreciprocate with respect to the wheels substantially parallel to theactive portion of the grinding surface, a work blade carried by andshiftable with the slide, the blade having a lengthwise inclinationcorresponding to the taper of a tapered work-piece, such inclinationbeing half the relative inclination of the wheel surfaces, and the slidehaving a pushing surface at one end of the blade and inclined crosswisewith respect to the active surface of the grinding wheel, saidinclination being the same as said lengthwise inclination; substantiallyas described.

5. In a centerless grinding machine, a grinding wheel, a regulatingwheel, the wheels having permanently adjacent surfaces relativelyinclined to define a tapering throat, a work carrying slide mounted toreciprocate with respect to the wheels, a work blade carried by andshiftable 'w-ith the slide, and a pushing surface at one end of theblade; substantially as described- 10, the regulating wheel 12 and thepocket bot- 6. In a centerless grinding machine, a grinding wheel, aregulating wheel, the wheels having permanently adjacent surfacesrelatively inclined to define a tapering throat, a work carrying slidemounted to reciprocate with respect to the wheels, a work blade carriedby and shiftable with the slide, a pushing surface at one end of theblade, a work supply chute having an outlet adjacent to one end of thethroat, and the slide having a barrier shiftable across said outlet;substantially as described.

7. In a centerless grinding machine, a grindthe other wheel a pair oftapering throats open in opposite directions, and means for thrusting atapered work-piece into one throat while dis charging another work-piecefrom the other throat; substantially as described.

8. In a centerless grinding machine, a grind ing wheel, a regulatingwheel, one of the wheels having oppositely inclined surfaces to formwith the otherwheel a pair of tapering throats open in oppositedirections, a work supporting blade arranged to enter each throat, and aslide carrying the blades and reciprocable between the wheels tosimultaneously carry a tapered workpiece into one throat and removeanother workpiece from the other throat; substantially as described.

9. In a centerless grinding machine, a grinding wheel, a regulatingwheel, one of the wheels having oppositely inclined surfaces to formwith the other wheel a pair of tapering throats open in oppositedirections, a slide reciprocating between the wheels and having a pairof work supporting blades; means for supplying tapered work-piecesalternately to the blades, and means for removing the ground work-piecesfrom the blades; substantially as described.

10. In a centerless grinding machine, a grinding wheel, a regulatingwheel, one of the wheels having oppositely inclined surfaces to formwith the other wheel a pair of tapering throats open in oppositedirections, a pair of work supply chutes having their outlets adjacentto the open ends of said throats, and a slide having work bladesinclined lengthwise in opposite directions and reciprocating between thewheels to carry tapered'work pieces alternately into said throats fromsaid chutes; substantially as described.

11. In a centerless grinding machine, a grinding wheel, a regulatingwheel, one of the wheels having oppositely inclined surfaces to formwith the other wheel a pair of tapering throats open in oppositedirections, a pair of work supply chutes having their outlets adjacentto the open ends of said throats, a slide reciprocating between thewheels and havingv a pair of work supporting blades movable alternatelyinto the grinding throats, and a pair of work discharging membersoutside 0! said chutes and alternately movable crosswise of the blades;substantially as described.

12. In a centerless grinding machine, a grinding wheel, a regulating.wheel, a pair of work supvporting blades adapted to enter alternatelythe space between the wheels, means for" supplying work piecesalternately to the blades, and a reciprocating slide supporting theblades; substantially as described. p 13. In a centerless grindingmachine, a grinding wheel, a regulating wheel, the adjacent surfaces ofthe wheels being similarly curved and divergent to receive a curved workpiece from one side, a work supporting blade curved to fit the peripheryof the work-piece, and a reciprocating slide for shifting the blade andworkpiece into and out of the divergent space between the wheels;substantially as described.

14. In a centerless grindingmachine, a grinding wheel, a regulatingwheel, the adjacent surfaces of the wheels being divergent to receive atapered work piece from one side, a work supporting blade to engage theperiphery of the work-piece, the blade sloping downwardly towards theregulating wheel,'a guide bar leading to the surface of the regulatingwheel, and a slide for reciprocating the blade; substantially as described.

15. Ina centerless grinding machine, a grinding wheel, a regulatingwheel, the adjacent surfaces of the wheels being concave anddivergent, awork supporting blade having a concave surface with a curvature similarto that of the whee1s,,and a slide supporting the blade and shiftable tocarry the blade and a supported work-piece into the space between thewheels; substantially as described.

16. In a centerless grinding machine, a grinding wheel, a regulatingwheel, the adjacent surfaces of the wheels being convex and divergent, awork supporting blade having a curvature similar to that of the wheels,and a slide reciprocating between the wheels and carrying the blade;substantially as described.

RAYMOND .H. CRAMER.

